The user account flow requires the authenticating user to interact with Google Drive via the browser.

See Embedded Credentials to connect with the adapter's embedded credentials and skip creating a custom OAuth app.

Instead of connecting with the adapter's embedded credentials, you can register an app to obtain the OAuthClientId and OAuthClientSecret.

Creating a custom OAuth app is optional as the adapter is already registered with Google Drive and you can connect with its embedded credentials. You might want to create a custom OAuth app to change the information displayed when users log into the Google Drive OAuth endpoint to grant permissions to the adapter.

Service accounts have silent authentication, without user authentication in the browser. You can also use a service account to delegate enterprise-wide access scopes to the adapter.

You need to create an OAuth application in this flow. You can then connect to Google Drive data that the service account has permission to access. See Custom Credentials for an authentication guide.

See Creating a Custom OAuth App for a procedure.